考虑摩擦滑移的板式橡胶支座连续梁桥地震反应分析

Seismic Response of Continuous Girder Bridge with Laminated Rubber Bearing Considering Friction Sliding

为研究板式橡胶支座滑动后对桥梁抗震性能的影响,对5个板式橡胶支座和1个铅芯橡胶支座进行了拟静力试验,对比分析考虑摩擦滑移后板式橡胶支座的力-位移滞回曲线、等效刚度、等效阻尼比及滞回耗能等力学特性与铅芯橡胶支座的异同,并以1座连续梁桥为例,通过非线性时程分析支座摩擦滑移对墩底曲率延性系数、墩底剪力、支座位移和残余位移及桥墩和支座滞回耗能等的影响,研究考虑支座摩擦滑移后桥梁的抗震性能,验证考虑摩擦滑移的板式橡胶支座在中小跨径连续梁桥上的应用。研究结果表明:考虑摩擦滑移的板式橡胶支座力学模型可用双线性滞回模型描述,加载位移大于200%后,板式橡胶支座和铅芯橡胶支座的滞回耗能接近;地震作用下考虑摩擦滑移的板式橡胶支座可耗散大量地震能量,但与主梁和限位装置的间隙有关,并且间隙的确定与地震动频谱特性有关,设计时应予以注意。

To investigate the seismic performance of bridges laminated rubber bearing considering friction sliding,quasi-static tests on five laminated rubber bearings and one lead rubber bearing were conducted.The similarities and differences of mechanical properties between laminated rubber bearing considering friction sliding and lead rubber bearing were compared and analyzed,such as force-displacement hysteresis curve,equivalent stiffness,equivalent damping ratio and hysteretic energy dissipation.Taking a continuous girder bridge as example,the influences of bearing fraction sliding on pier bottom curvature ductility coefficient,pier bottom shear force,bearing displacement and residual displacement and hysteretic energy dissipation of piers and bearings were analyzed by nonlinear time history analysis.The seismic performance of bridgeconsidering friction sliding was investigated,and the application of laminated rubber bearings considering friction on a small and medium span continuous bridge was verified.The results show that the hysteretic mechanical model of laminated rubber bearing considering friction sliding can be described by bilinear hysteretic model;after loading displacement is greater than 200%,the hysteretic energies of laminated rubber bearings and lead rubber bearing are closer;the laminated rubber bearing considering friction slipping can dissipate significant amount of earthquake energy,which relates to the gap between main girder and stop block,and the determination of the gap is related to the spectral characteristics of the earthquake,which should be noticed in the seismic design.